CIC&lpar;Copper-Invar™-Copper&rpar; FoilCIC foil is used for printed circuit boards with ground and power planes and metal cores&period; The low CTE&lpar;coefficient of thermal expansion&rpar;over a broad temperature range &lpar;-55ºC-125ºC&rpar; is crucial for aerospace and some special fields&period;Structure&colon;